Item 3.03 Material Modification to Rights of Security Holders.

On February 12, 2013, Plug Power Inc. (the "Company") and Broadridge Corporate Issuer Solutions, Inc., as rights agent ("Broadridge"), entered into an Amendment No. 4 (the "Amendment") to Shareholders Rights Agreement, dated as of June 23, 2009 (as amended by Amendment No. 1 to Shareholder Rights Agreement, dated as of May 6, 2011, Amendment No. 2 to Shareholder Rights Agreement, dated March 16, 2012, and Amendment No. 3 to Shareholder Rights Agreement, dated March 23, 2012 the "Rights Agreement"), between the Company and Broadridge.

The Amendment amends the Rights Agreement to provide that, generally, any beneficial ownership of shares of our common stock by any investor acquiring shares of our common stock pursuant to the February 2013 underwritten public offering with Roth Capital Partners as managing underwriter (the "Offering") will not cause the preferred stock purchase rights to become exercisable under the Rights Agreement, so long as any such investor and its affiliates and associates do not at any time beneficially own shares of our common stock equaling or exceeding one-half percent more than the percentage of the then outstanding shares of common stock beneficially owned by such investor and its affiliates and associates immediately following the closing of the Offering. The Amendment also provides that any beneficial ownership of shares of our common stock by affiliates and associates of AWM Investments Company, including but not limited to Special Situations Technology Fund, L.P., Special Situations Technology Fund II, L.P., and Special Situations Private Equity Fund, L.P., or SSF collectively, will not cause the preferred stock purchase rights to become exercisable under the Rights Agreement, so long as SSF and its affiliates and associates do not at any time beneficially own shares of our common stock equaling or exceeding three percent more than the percentage of the then outstanding shares of common stock beneficially owned by SSF and its affiliates and associates immediately following the closing of the Offering.

The foregoing description of the Amendment does not purport to be complete and is qualified in its entirety by reference to the Amendment, which is filed as Exhibit 4.1 hereto and is incorporated herein by reference.

---

Item 9.01. Financial Statements and Exhibits

(d) Exhibits.

4.1 Amendment No. 4 to Shareholder Rights Agreement dated as of February 12, 2013 by and between Plug Power Inc. and Broadridge Corporate Issuer Solutions, Inc., as Rights Agent.

---